舰船推进轴系的螺旋桨激励力传递特性

Transmission characteristics of propeller excitation for naval marine propulsion shafting

螺旋桨激励力会通过轴系向各轴承基座传递,并激发船体结构产生振动声辐射问题。为掌握螺旋桨不同方向激励力通过轴系的传递规律,利用船舶推进轴系试验台,在轴系固有特性计算与测试的基础上,测试分析螺旋桨水平、垂向与纵向激励力通过轴系向3个轴承基座的传递特性。结果表明:单方向激励力作用下,轴系会产生不同方向的耦合振动,并在基座处产生3个方向的振动,其中轴系振动固有频率有明显体现;不同方向的激励力传递路径不同,水平激励在艉轴后轴承基座处产生较大水平振动,垂向激励在艉轴后轴承和推力轴承基座处产生较大垂向振动,纵向激励在推力轴承基座处产生较大纵向振动,螺旋桨激励力通过轴系向艉轴前轴承基座的传递相对较弱;与垂向激励相比,水平激励会在3个轴承基座处产生更大的振动响应。

The propeller excitation transferred through shafting to the bearing bases will induce structuralvibration of the ship. To obtain the transmission laws of the propeller excitation in different directions, thetransmission characteristics of the propeller excitation in the horizontal direction, vertical direction, andlongitudinal direction through shafting to bearing bases are studied based on the shafting natural vibrationcalculation and the measurement from a general marine propulsion shafting test rig. The research resultsshow that the exciting force applied at the propeller in any direction could induce shafting coupled vibra-tion in different directions and structural vibrations in three directions at the bearing bases; the transmis-sion paths differ in directions, with the exciting force in the horizontal direction arousing greater vibrationat the aft stern bearing base horizontally, the exciting force in the vertical direction arousing greater vibra-tion at the aft stern bearing base and the thrust bearing base vertically, and the exciting force in the longitu-dinal direction arousing greater vibration at the thrust bearing base longitudinally. Moreover, the transmis-sion of propeller exciting force to the forward stern bearing base is relatively weak, and the excitation in thehorizontal direction induces greater vibratory response compared to that in the vertical direction.